Tools used

• Card: NXP NTAG424 DNA https://zipnfc.com/nfc-pvc-card-credit-card-size-ntag424-dna.html
• Raspiblitz node running:
• Core Lightning
• LNbits with the Bolt Cards extension
• Boltcard NFC Card Creator Android app

Preparation

Run the latest experimental version of Raspiblitz

• menu -> PATCH
• REPO: rootzoll
• BRANCH: dev

To update LNbits to the latest commit in the master branch

• Run:
  config.scripts/bonus.lnbits.com sync

Expose LNbits on a public domain

• can use a cheap, minimal VPS tunneled from the node with Tailscale
• point an A-record with a subdomain to the public IPaddress of the VPS
• download Tailscale on the node and the VPS: https://tailscale.com/download/linux
• log in on both (consider using a dedicated github account)
• on the VPS set up nginx to forward a subdomain to the TailscaleIP:LNbitsPORT on the node: https://github.com/openoms/bitcoin-tutorials/tree/master/nginx

Download the Boltcard NFC Card Creator Android app

• https://play.google.com/store/apps/details?id=com.lightningnfcapp
• https://github.com/boltcard/bolt-nfc-android-app

Steps to set up a Bolt Card

• open LNbits on the public domain
• create a wallet and save the link
• add the Bolt Cards extension (to serve the boltcard API)
• open the extension and create a bolt card
• scan the QRcode with the keys with the Boltcard NFC Card Creator app
• write the keys on a blank card by touching it to the phone

Test

• Breez
• Wallet of Satoshi (didn't work for me)
• NFC enabled webwallet like the LNbits TPOS: https://clnbits.diynodes.com/tpos/gyZytJ3eLygXbe7EsJoi8C
• NFC enabled PoS terminals

• https://github.com/boltcard/boltcard
• https://github.com/boltcard/bolt-nfc-android-app
• https://github.com/lnbits/lnbits/tree/main/lnbits/extensions/boltcards